Polyesters with specified crystallization half-times

ABSTRACT

wherein A is an aliphatic, aromatic, or heterocyclic group; R1 is selected from the group consisting of 1,4-butanediol residue and 1,4-cyclohexanedimethanol residue; R2 is neopentanediol residue; m is between 50 and 99 inclusive; n is between 1 and 50 inclusive; x is between 1 and 200 inclusive; and wherein said semi-crystalline polyester exhibits a minimum crystallization half-time of about 0.3 minutes or greater, or about 0.5 minutes or greater or about 0.6 minutes or greater or about 0.7 minutes or greater is described. The polyesters of the present invention may in various embodiments demonstrate one or more desirable performance characteristics and accordingly are particularly useful in applications and utilities wherein those high levels of performance for such characteristics are required. A process for forming the semi-crystalline polyester is also disclosed.

FIELD OF THE INVENTION

The present invention relates generally to improved polyesters,compositions containing such improved polyesters and articles such asfilms and injection molded articles formed from such improvedpolyesters.

BACKGROUND OF THE INVENTION

Polyesters are often viewed as the world's most used class of polymers,with published world production volumes (including recycling) recentlyreported to be well in excess of 75 million tons. This level ofcommercial success is likely attributable in part to polyesters'attractive combination of relative cost, manufacturability andcompetitive performance attributes. Polyester's physical, chemical andthermal properties make them useful and desirable for a wide variety ofend-use applications. Polyethylene terephthalate (PET) is probably oneof the most popular types of polyester for many end-uses.

Despite these commercial volumes, polyesters generally have had morelimited success in penetrating certain end-use markets, for example inthe manufacture of injection molded articles, especially those used inhigher-temperature applications such as under-the-hood vehicle parts.For example, U.S. Pat. No. 4,486,561 provides that PET “is not alwaysthe material of choice for injection molding usage because relativelyhigh mold temperatures, e.g., 120°-140° C., must be utilized to insuregood moldability”. Attempts to develop commercially cost-competitiveinjection-moldable and/or higher-melting point temperature polyestershave met with limited success.

Also, as noted in U.S. Pat. No. 4,355,080, issued to the assignee of thepresent invention, certain older-generation polyesters generally “havenot found acceptance as sheeting materials for signs, windows and thelike because of embrittlement and surface deterioration on ageing,particularly under outdoor weathering conditions”. The invention of the'080 patent addresses this issue via an invention wherein “acrylicpolymers can be compression laminated to the surface of polyestersubstrates to produce a permanently bonded composite sheet havingexcellent retention of surface and physical properties on extendedweathering.” Though this solution is purported to addressweatherability, it requires additional materials and processing stepsthat add significant manufacturing cost. Also notable on polyesterweatherability is U.S. Pat. No. 7,132,499, which describes a polyestercontainer with improved weatherability wherein the container is made ofa polyester resin composition comprising (A) 100 parts by weight of apolyester resin and (B) 0.01 to 10 parts by weight of a certain triazineultraviolet absorber. As with many general attempts to resolve polymerdeficiencies with additives, the additive materials can increase costand impact processability of the composition and may also have limitedefficacy and undesirable side-effects on other aspects of compositionperformance.

Modifications within the general polyester polymer structure have beenexplored to generally improve various aspects of polyester performance.For example U.S. Pat. No. 3,256,241 describes polyesters that areprepared by reacting 1,4-bicyclo[2.2.2]octanedicarboxylic acid, or anester-forming derivative thereof, with a dihydroxy compound or anester-forming derivative thereof. These polyester products are generallycharacterized by good stability to light, both outdoors and indoors;however, their crystallization half-time and other characteristics makethem less compatible (if not incompatible) for processing in equipmentand systems currently utilized in manufacture of end products from morecommon polyesters such as polyethylene terephthalate (PET). Further,none of the polyesters described in the '241 patent are expected toperform well in forming injection molded articles or reach melt pointssuitable for high-temperature applications.

Despite these techniques to improve polyesters and polyestercompositions as to meet the newest and highest performancespecifications, the need remains for improved polyesters that meetprocessability requirements for existing end-product manufacturingsystems while cost-effectively satisfying performance specifications andmaintaining them over time.

SUMMARY OF THE INVENTION

In a first aspect, the present invention relates to a semi-crystallinepolyester comprising a repeat unit of the formula:

-   -   wherein A is an aliphatic, aromatic, or heterocyclic group; R₁        is selected from the group consisting of 1,4-butanediol and        1,4-cyclohexanedimethanol residue; R₂ is neopentanediol residue;        m is between 50 and 99 inclusive; n is between 1 and 50        inclusive; x is between 1 and 200 inclusive; and wherein said        semi-crystalline polyester exhibits a minimum crystallization        half-time of about 0.3 minutes or greater, or about 0.5 minutes        or greater or about 0.6 minutes or greater or about 0.7 minutes        or greater.

In another aspect, the present invention relates to a composition thatincludes a polyester of the first aspect of the present invention.

In still another aspect, the present invention relates to a film,particularly a monolayer film, that includes a semi-crystallinepolyester of the first aspect of the present invention.

In yet another aspect, the present invention relates to an injectionmolded article that includes a semi-crystalline polyester of the firstaspect of the present invention.

In yet another aspect, the present invention is directed to a method formaking a semi-crystalline polyester having a repeat unit of the formula:

-   -   wherein A is an aliphatic, aromatic, or heterocyclic group; R₁        is selected from the group consisting of 1,4-butanediol and        1,4-cyclohexanedimethanol residue; R₂ is neopentanediol residue;        m is between 50 and 99 inclusive; n is between 1 and 50        inclusive; x is between 1 and 200 inclusive, or between 80 and        160 inclusive; and wherein said semi-crystalline polyester        exhibits a minimum crystallization half-time of about 0.3        minutes or greater, or about 0.5 minutes or greater or about 0.6        minutes or greater or about 0.7 minutes or greater;    -   wherein the method includes the steps of        -   (A) contacting a compound of the formula

-   -   -   with (i) a transition metal catalyst comprising a palladium            compound and (ii) an oxidizing agent, optionally in the            presence of at least one of            -   (I) a compound of the formula

-   -   -   -   -   wherein R is chosen from hydrogen; and C₁-C₁₂ alkyl,                    optionally substituted by one or more of groups                    chosen from C₁-C₆ alkoxy, halo, nitro, and cyano; R*                    is chosen from hydrogen; C₁-C₁₂ alkyl, optionally                    substituted by one or more of groups chosen from                    C₁-C₆ alkoxy, halo, nitro, and cyano; and an alkali                    metal cation; or

            -   (II) a compound having at least one C₁-C₁₂ alkanoyloxy                moiety of the formula

-   -   -   -   -   to afford a compound of the formula

-   -   -   -   -   wherein each R₁ is independently hydrogen or a group                    of the formula

-   -   -   (B) contacting the compound of the formula

-   -   -   wherein each R₁ is independently hydrogen or a group of the            formula

-   -   -   with carbon monoxide in the presence of a strong acid,            followed by quenching with at least one of (i) water or (ii)            an alcohol of the formula R—OH, to afford compound of the            formula

-   -   -   (C) optionally treating the compound of the formula

-   -   -   with an oxidizing agent to afford a compound of the formula:

-   -   -   (D) reacting at least one of the compounds

-   -   -   with a difunctional hydroxyl compound selected from the            group consisting of 1,4-butanediol, neopentyl glycol, and            1,4-cyclohenxanedimethanol; and        -   (E) subjecting the resulting product to one or more            polycondensation reaction steps to form a polyester.

Further aspects of the invention are as disclosed and claimed herein.

DETAILED DESCRIPTION

The term “residue”, as used herein, means any organic structureincorporated into a polymer through a polycondensation and/or anesterification reaction from the corresponding monomer. The term“repeating unit”, as used herein, means an organic structure having adicarboxylic acid residue and a diol residue bonded through acarbonyloxy group. The term “semi-crystalline”, as used herein,indicates that the polyesters have a substantially amorphous yetpartially crystalline morphology, meaning that the polyesters comprisesubstantially unordered regions of polymer along with some orderedregions. The crystallization half-times of the polyesters of the presentinvention are in part indicative of their characterization assemi-crystalline.

The present invention, in a first aspect, is directed to asemi-crystalline polyester that includes a repeat unit of the formula(II)

-   -   wherein A is an aliphatic, aromatic, or heterocyclic group; R₁        is selected from the group consisting of 1,4-butanediol and        1,4-cyclohexanedimethanol residues; R₂ is neopentanediol        residue; m is between 50 and 99 inclusive; n is between 1 and 50        inclusive; x is between 1 and 200 inclusive, or between 80 and        160 inclusive; and wherein said semi-crystalline polyester        exhibits a minimum crystallization half-time of about 0.3        minutes or greater, or about 0.5 minutes or greater or about 0.6        minutes or greater or about 0.7 minutes or greater. The        polyesters of this aspect of the present invention, in various        embodiments, demonstrate one or more desirable performance        characteristics and accordingly are particularly useful in        applications and utilities wherein those high levels of        performance in such characteristics are required.

“Polyester” as used herein is meant to generally include withoutlimitation homopolyesters as well as copolyesters, terpolyesters and thelike and are typically prepared by reacting a difunctional carboxylicacid or its ester, often a dicarboxylic acid, or mixtures of such acidsor esters, with a difunctional hydroxyl compound, often a diol orglycol, or mixtures of such diols or glycols. Alternatively, thedifunctional carboxylic acid may be a hydroxy carboxylic acid and thedifunctional hydroxyl compound may be an aromatic nucleus bearing 2hydroxyl substituents such as, for example, hydroquinone. Polyesters andpolyester manufacture are generally well known and are exemplified infor example U.S. Pat. No. 7,781,562, assigned to the assignee of thepresent invention, the contents and disclosure of which are herebyincorporated herein by reference.

The substituent or group “A” in the above formula is selected from thegroup consisting of an aliphatic group, an aromatic group and aheterocyclic group. Suitable examples for group A include residues of,without limitation, succinic acid, sebacic acid, azelaic acid, adipicacid, dimer acid such as that commercially available under the tradename Empol® 1010, glutaric acid, 1,4-cyclohexanedicarboxylic acid,isophthalic acid, carbonic acid, pimelic acid, dimethylmalonic acid,2,6-naphthalenedicarboxylic acid, phthalic acid, suberic acid,1,12-dodecanedicarboxylic acid, 4,4′-sulfonyldibenzoic acid, diglycolicacid, 1,3-phenylenedioxydiacetic acid, 5-(sodiosulfo)isophthalic acidand 4,4′-stilbenedicarboxylic acid.

In one or more embodiments, R₁ and R₂ are each independently selectedfrom the group consisting of 1,2-ethylene glycol, 1,3-propanediol,1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol,1,10-decanediol, neopentyl glycol, neopentanediol,2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol,1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol,2,2,4,4,-tetramethyl-1,3-cyclobutanediol, diethylene glycol, triethyleneglycol, isosorbide, poly(oxytetramethyleneglycol),bicyclo[2.2.2]octane-1,4-dimethanol and 1,4-benzenedimethanol residuesand mixtures thereof. In one or more embodiments, R₁ is selected fromthe group consisting of 1,2-ethylene glycol, 1,3-propanediol,1,4-butanediol, neopentyl glycol, 1,4-cyclohexanedimethanol andbicyclo[2.2.2]octane-1,4-dimethanol residues and R₂ is selected from thegroup consisting of 1,2-ethylene glycol, 1,4-butanediol, neopentanediol,neopentyl glycol and 2,2,4,4,-tetramethyl-1,3-cyclobutanediol residues.In one or more embodiments, R₁ is 1,4-butanediol residue. In one or moreembodiments, R₁ is 1,4-cyclohexanedimethanol residue. In one or moreembodiments, R₂ is neopentanediol residue.

The value for “m” may be between 50 and 99 inclusive, or between 65 and95 inclusive, or between 80 and 90 inclusive. The value for n may bebetween 1 and 50 inclusive or between 5 and 35 inclusive, or between 10and 20 inclusive. The value for x may be between 1 and 200 inclusive.Accordingly, semi-crystalline polyesters of the present invention mayinclude other polyester repeat units. The semi-crystalline polyesters ofthe present invention preferably include from 1 to 100 mol % of therepeat units of the formula (II) above.

Such other polyester repeat units repeat units are well known in the artand are exemplified in above-referenced U.S. Pat. No. 7,781,562. Inbrief, such repeat units are prepared by the reaction of one or moredifunctional carboxylic acids and/or multifunctional carboxylic acidswith one or more difunctional hydroxyl compounds and/or multifunctionalhydroxyl compounds. Typically, the difunctional carboxylic acid can be adicarboxylic acid and the difunctional hydroxyl compound can be adihydric alcohol such as, for example, glycols and diols. The term“glycol” as used in this application includes, but is not limited to,diols, glycols, and/or multifunctional hydroxyl compounds, for example,branching agents. Alternatively, the difunctional carboxylic acid may bea hydroxy carboxylic acid such as, for example, p-hydroxybenzoic acid,and the difunctional hydroxyl compound may be an aromatic nucleusbearing 2 hydroxyl substituents such as, for example, hydroquinone.Thus, for example, the dicarboxylic acid residues may be derived from adicarboxylic acid monomer or its associated acid halides, esters, salts,anhydrides, or mixtures thereof. As used herein, therefore, the termdicarboxylic acid is intended to include dicarboxylic acids and anyderivative of a dicarboxylic acid, including its associated acidhalides, esters, half-esters, salts, half-salts, anhydrides, mixedanhydrides, or mixtures thereof, useful in a reaction process with adiol to make polyester. Furthermore, as used in this application, theterm “diacid” includes multifunctional acids, for example, branchingagents.

It should be noted that the notation used in the above formulas for therepeat unit does not alone specify or indicate any particular polymermorphology. Nonetheless, in one or more embodiment, the polyester of thepresent invention is a semi-crystalline polyester.

In an embodiment, the semi-crystalline polyesters of the presentinvention have a minimum crystallization half-time of about 0.3 minutesor greater, or about 0.5 minutes or greater or about 0.6 minutes orgreater or about 0.7 minutes or greater.

In one or more embodiments, the semi-crystalline polyesters of thepresent invention have a melt point of from 240° C. to 275° C., or from255° C. to 275° C. when measured using DSC techniques known in the artwith standard commercially available equipment. Particularly suitablesemi-crystalline copolymers of the present invention have a melt pointof from 240° C. to 275° C. and include 1,4-cyclohexanedimethanol residueas R₁.

The semi-crystalline polyesters of the present invention, in one or moreembodiments, exhibit improved weatherability. Weatherability andanalytical methods for its measurement are well known in the art and areexemplified by ASTM methods D1435-12 and D4364-13 (accelerated).

In other aspect, the present invention is directed to a method forforming a polyester that includes repeat units of the formula (I) above.The method of the present invention includes the steps of

-   -   (A) contacting a compound of the formula

-   -   with (i) a transition metal catalyst comprising a palladium        compound and (ii) an oxidizing agent, optionally in the presence        of at least one of        -   (I) a compound of the formula

-   -   -   -   wherein R is chosen from hydrogen; and C₁-C₁₂ alkyl,                optionally substituted by one or more of groups chosen                from C₁-C₆ alkoxy, halo, nitro, and cyano; R* is chosen                from hydrogen; C₁-C₁₂ alkyl, optionally substituted by                one or more of groups chosen from C₁-C₆ alkoxy, halo,                nitro, and cyano; and an alkali metal cation; or

        -   (II) a compound having at least one C₁-C₁₂ alkanoyloxy            moiety of the formula

-   -   -   -   to afford a compound of the formula

-   -   -   -   wherein each R₁ is independently hydrogen or a group of                the formula

-   -   (B) contacting the compound of the formula

-   -   wherein each R₁ is independently hydrogen or a group of the        formula

-   -   with carbon monoxide in the presence of a strong acid, followed        by quenching with at least one of (i) water or (ii) an alcohol        of the formula R—OH, to afford compound of the formula

-   -   (C) optionally treating the compound of the formula

-   -   with an oxidizing agent to afford a compound of the formula:

-   -   (D) reacting at least one of the compounds

-   -   with a difunctional hydroxyl compound selected from the group        consisting of 1,4-butanediol, neopentyl glycol, and        1,4-cyclohenxanedimethanol; and    -   (E) subjecting the resulting product to one or more        polycondensation reaction steps to form a polyester.

Suitable compounds and methods for their manufacture are known in theart and described for example in WO2018/075301 A1 assigned to theassignee of the present invention, the contents and disclosure of whichare each hereby incorporated herein by reference. Particularly suitablecompounds are bicyclo [2.2.2] octane compounds selected from the groupconsisting of 4-(methoxycarbonyl)bicyclo[2.2.2]octane-1-carboxylic acidand dimethyl bicyclo[2.2.2]octane-1,4-dicarboxylate.

The present invention, in another aspect, is directed to compositionthat includes a semi-crystalline polyester including a repeat unit ofthe formula (II):

wherein A is an aliphatic, aromatic, or heterocyclic group; R₁ isselected from the group consisting of 1,4-butanediol residue and1,4-cyclohexanedimethanol residue; R₂ is neopentanediol residue; m isbetween 50 and 99 inclusive; n is between 1 and 50 inclusive; x isbetween 1 and 200 inclusive, or between 80 and 160 inclusive; andwherein said semi-crystalline polyester exhibits a minimumcrystallization half-time of about 0.3 minutes or greater, or about 0.5minutes or greater or about 0.6 minutes or greater or about 0.7 minutesor greater.

The compositions of the present invention preferably may include atleast 5 weight percent or at least 10 weight percent or least 20 weightpercent or at least 30 weight percent or at least 40 weight percent orleast 50 weight percent of the semi-crystalline polyester of the presentinvention.

The compositions of the present invention may further include at leastone other polymer. Suitable polymers for the composition of the presentinvention include by way of non-limiting example polycarbonates,acrylics, polystyrenes, cellulose esters, polydimethylsiloxanes and thelike.

The compositions of the present invention also may contain one or moreother conventional additives and ingredients. For example, additivessuch as reinforcements, mold release additives, fillers, surfacefriction modifiers, light and heat stabilizers, extrusion aids,antistatic agents, colorants, dyes, pigments, fluorescent brighteners,antimicrobials, anticounterfeiting markers, hydrophobic and hydrophilicenhancers, viscosity modifiers, slip agents, tougheners, adhesionpromoters, and the like may be used. Colorants, sometimes referred to astoners, may be added to impart a desired neutral hue and/or brightnessto the composition in end-use applications that specify such a feature.Optional ingredients such as these, as well as their chosenconcentrations, are typically selected based on an individualcomposition's specific end-use specifications and application.

In another aspect, the present invention is directed to a film includingthe semi-crystalline polyester of the present invention. In anembodiment, the film is a monolayer film. Films of the present inventionare, in an embodiment, from 1 mil to about 14 mils in thickness. Thefilm of the present invention may be manufactured by methods well knownthe art as exemplified by U.S. Pat. No. 5,958,581, the contents anddisclosure of which are incorporated herein by reference. An importantfeature of the film of the present invention is that it is capable ofbeing oriented uniaxially or biaxially. Methods and equipment formanufacturing oriented polyester films, as well as oriented polyesterfilms per se, are well known in the art and for example are described inU.S. Pat. Nos. 4,020,141 and 6,368,532, the contents and disclosure ofwhich are hereby incorporated herein by reference. Accordingly, in oneor more embodiments, the film of the present invention is a biaxiallyoriented film or a biaxially oriented monolayer film.

The film of the present invention may be generally useful in end-useapplications wherein the film is exposed for an extended period toweathering, sunlight and/or ultraviolet radiation. Accordingly, in oneillustrative non-limiting example, the film of the present invention isuseful as the backsheet of photovoltaic module. Photovoltaic modules andtheir manufacture as well as module backsheets are generally known inthe art as exemplified by U.S. Pat. No. 9,082,91262 and U.S. PublishedPatent Application No. US2008/0053512A1, the contents and disclosure ofwhich are each hereby incorporated herein by reference.

In another aspect, the present invention is directed to an injectionmolded article that includes the semi-crystalline polyester of thepresent invention. Injection molded articles are any articles formedusing known and conventional injection molding methods and equipmentsuch as that described for example in U.S. Pat. Nos. 5,707,667 and3,533,594, the contents and disclosure of which are hereby incorporatedherein by reference.

The following examples, while provided to illustrate with specificityand detail the many aspects and advantages of the present invention, arenot be interpreted as in any way limiting its scope. Variations,modifications and adaptations which do depart of the spirit of thepresent invention will be readily appreciated by one of ordinary skillin the art. Throughout these examples, the following experimental andanalytical techniques were employed in measuring the parametersindicated when these parameters were in fact measured:

The inherent viscosity of the polyesters was determined in 60/40 (wt/wt)phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25° C.

The melting temperature (T_(m)) and glass transition temperature (T_(g))were determined by using a TA Instruments Q2000 model differentialscanning calorimeter (DSC). The sample was weighed to approximately 3mgs and placed into an aluminum pan. An appropriate lid was placed ontop and crimped into place. Then the sample was placed into the DSC cellaccompanied by an empty aluminum pan to serve as a reference. Thefurnace lid was placed over the cell, and the temperature scan began.The instrument cooled the sample to 0° C. to initiate the 1st heatingscan. During this heating scan, the sample was heated at a rate of 20°C./min to the maximum temperature then held isothermally for 1 minute toensure the sample had fully melted. Next, the instrument cooled thesample at a rate of 20° C./min to 0° C. and held isothermally for 30seconds to allow for instrument equilibration. Then, the sample washeated a 2nd time to the maximum temperature at a rate of 20° C./min.The data was transferred to Universal Analysis software and anytransitions such as glass transition temperature (T_(g)),crystallization on heating (T_(ch)), T_(m), or crystallization oncooling (T_(cc)) were integrated.

The crystallization halftime was measured on a Perkin Elmer 8500 DSCinstrument. The measurement was made by measuring the heat flow of thesample versus temperature. Once a sample was prepared, the Pyrusoperating software was opened, and the appropriate identifyinginformation was inputted. The sample was loaded into the DSC cell alongwith an empty pan to serve as a reference. The furnace lid was put intoplace and the test began. The instrument heated the sample from 0° C. toT_(max) and was held isothermally at T_(max) for 2 minutes to ensurefull melting of the sample. Then, the sample was cooled at the fastestrate the instrument was designed to reach, up to 600° C./min, to thefirst designated crystallization temperature and held isothermally for aprescribed amount of time, typically 30 minutes. If there wereadditional crystallization temperatures, the sample would then bereheated to T_(max) at the 600° C./min rate and held isothermally for 2minutes. Then it would be cooled to the next crystallization temperatureas described previously. This pattern of heating, cooling, andisothermal holds would continue until all the crystallizationtemperatures had been tested. Once the testing was complete, the datawas analyzed on a heat flow versus time graph and by integrating theonset of the isothermal hold and the maximum of the crystallizationpeak. The time at the onset of the isothermal hold was subtracted fromthe time at the peak of the maximum, and the result was thecrystallization halftime at that crystallization temperature. The“minimum crystallization half-time” (sometimes referred to hereint_(1/2)) is the minimum length of time required to achieve approximatelyhalf of the maximum crystallinity achievable at a given crystallizationtemperature. t_(1/2) depends in part on the crystallization temperatureT_(c), and t_(1/2) is typically at its minimum, i.e., maximumcrystallization rate, at a temperature approximately half way betweenthe glass transition temperature (T_(g)) and the melt temperature(T_(m)).

Example 1 (Control)

A monomer composition of a mixture of 0.10 mol of4-(methoxycarbonyl)bicyclo[2.2.2]octane-1-carboxylic acid, 0.15 mol of1,4-butanediol, 0.0029 g of titanium oxide was placed in a 250-mL flaskequipped with an inlet for nitrogen, a metal stirrer, and a shortdistillation column. The flask was placed in a metal bath at 200° C. Thestirring speed was set to 200 RPM. The contents of the flask were heatedat 200° C. for 5 minutes and then the temperature was graduallyincreased to 255° C. over 3 hours. The reaction mixture was held at 255°C. for 10 minutes and then vacuum was gradually applied over the next 10minutes until the pressure inside the flask reached 100 mmHg. Thepressure inside the flask was further reduced to 0.5 mmHg over the next5 minutes. The stirring speed was set to 100 RPM. A pressure of 0.5 mmHgwas maintained for a total time of 3 hours to remove excess unreacteddiols. A polyester (Poly(1,4-butylene1,4-bicyclo[2.2.2]octanedicarboxylate) with an IV of 0.872, a T_(g) of53.6° C., and a T_(m) of 193.6° C. was obtained. Rapid crystallizationwas observed and therefore crystallization half-time was not measured.

Example 2

The procedure used to form a polyester as set forth in Example 1 wasemployed in Example 2 using the following monomer composition: 0.10 molof dimethyl bicyclo[2.2.2]octane-1,4-dicarboxylate, 0.135 mol of1,4-butanediol, and 0.015 mol of neopentyl glycol. A polyester(Poly[(1,4-butylene1,4-bicyclo[2.2.2]octanedicarboxylate)-co-(neopentylene1,4-bicyclo[2.2.2]octanedicarboxylate)], 1,4-butylene:neopetylene=90:10)with an IV of 0.905, a T_(g) of 47.0° C., and a T_(m) of 182.0° C. wasobtained. The crystallization half-time for this material was thenmeasured at multiple temperatures with measured crystallizationhalf-times as follows: 2.1 min at 80° C., 1.0 min at 90° C., 0.7 min at100° C., 0.6 min at 105° C., 0.6 min at 110° C., 0.7 min at 115° C., 0.8min at 120° C., 1.3 min at 130° C., and 2.1 min at 140° C. The sampletherefore is characterized by a minimum crystallization half-time of 0.6minutes.

Example 3

The procedure used to form a polyester as set forth in Example 1 wasemployed in Example 3 using the following monomer composition: 0.10 molof dimethyl bicyclo[2.2.2]octane-1,4-dicarboxylate, 0.132 mol of1,4-butanediol, and 0.018 mol of neopentyl glycol. A polyester(Poly[(1,4-butylene1,4-bicyclo[2.2.2]octanedicarboxylate)-co-(neopentylene1,4-bicyclo[2.2.2]octanedicarboxylate)], 1,4-butylene:neopetylene=88:12)with an IV of 0.998, a T_(g) of 48.0° C., and a T_(m) of 165.0° C. wasobtained. The crystallization half-time for this material was thenmeasured at multiple temperatures with measured crystallizationhalf-times as follows: 0.9 min at 80° C., 0.4 min at 90° C., 0.3 min at100° C., 105° C., 110° C., and 115° C., 0.4 min at 120° C., 0.9 min at130° C., and 1.7 min at 140° C. The sample therefore is characterized bya minimum crystallization half-time of 0.3 minutes.

Example 4

The procedure used to form a polyester as set forth in Example 1 wasemployed in Example 4 using the following monomer composition: 0.10 molof dimethyl bicyclo[2.2.2]octane-1,4-dicarboxylate, 0.128 mol of1,4-butanediol, and 0.023 mol of neopentyl glycol. A polyester(Poly[(1,4-butylene1,4-bicyclo[2.2.2]octanedicarboxylate)-co-(neopentylene1,4-bicyclo[2.2.2]octanedicarboxylate)], 1,4-butylene:neopetylene=85:15)with an IV of 0.904, a T_(g) of 42.0° C., and a T_(m) of 151.0° C. wasobtained. The crystallization half-time for this material was thenmeasured at multiple temperatures with measured crystallizationhalf-times as follows: 10.8 min at 80° C., 5.8 min at 90° C., 4.6 min at100° C., 4.5 min at 105° C., 4.9 min at 110° C., 5.6 min at 115° C., 7.2min at 120° C., 14.2 min at 130° C., and 20.0 min at 140° C. The sampletherefore is characterized by a minimum crystallization half-time of 4.5minutes.

Example 5 (Control)

A mixture of 0.10 mol of4-(methoxycarbonyl)bicyclo[2.2.2]octane-1-carboxylic acid, 0.11 mol of1,4-cyclohexanedimethanol (cis/trans=31/69), 0.0029 g of titanium oxidewas placed in a 250-mL flask equipped with an inlet for nitrogen, ametal stirrer, and a short distillation column. The flask was placed ina metal bath at 200° C. The stirring speed was set to 200 RPM. Thecontents of the flask were heated at 200° C. for 5 minutes and then thetemperature was gradually increased to 255° C. over 3 hours. Thetemperature was further gradually increased to 280° C. over 10 minutes.The reaction mixture was held at 280° C. The pressure inside the flaskwas reduced to 400 mmHg over 5 minutes. The pressure was further reducedto 100 mmHg and the stirring speed was reduced to 100 RPM over 5minutes. The pressure was further reduced to 0.5 mmHg and the stirringspeed was reduced to 50 RPM over 5 minutes. A pressure of 0.5 mmHg wasmaintained for a total time of 3 hours to remove excess unreacted diols.A polyester (Poly(1,4-cyclohexanedimethylene1,4-bicyclo[2.2.2]octanedicarboxylate) with an IV of 0.629, a T_(g) of131° C., and a T_(m) of 299.0° C. was obtained. The crystallizationhalf-time for this material was then measured at multiple temperatureswith measured crystallization half-times as follows: 0.1 min at 210° C.,0.2 min at 220° C., and 0.3 min at 230° C. The crystallization half-timefor this material at 170° C., 180° C., 190° C., and 200° C. were tooshort (less than 0.1 min) to be accurately determined.

Example 6

The procedure used to form a polyester as set forth in Example 5 wasemployed in Example 7 using the following monomer composition: 0.10 molof 4-(methoxycarbonyl)bicyclo[2.2.2]octane-1-carboxylic acid, 0.097 molof 1,4-cyclohexanedimethanol (cis/trans=31/69), and 0.018 mol ofneopentyl glycol. A polyester (Poly[(1,4-cyclohexanedimethylene1,4-bicyclo[2.2.2]octanedicarboxylate)-co-(neopentylene1,4-bicyclo[2.2.2]octanedicarboxylate)],1,4-cyclohexanedimethylene:neopetylene=88:12) with an IV of 0.689, aT_(g) of 123° C., and a T_(m) of 274° C. was obtained. Thecrystallization half-time for this material was then measured atmultiple temperatures with measured crystallization half-times asfollows: 2.4 min at 160° C., 1.4 min at 170° C., 0.5 min at 175° C., 0.4min at 185° C., 0.4 min at 195° C., 0.5 min at 205° C., and 0.8 min at215° C. The sample therefore was characterized by a minimumcrystallization half-time of 0.4 minutes.

Example 7

The procedure used to form a polyester as set forth in Example 5 wasemployed in Example 8 using the following monomer composition: 0.10 molof 4-(methoxycarbonyl)bicyclo[2.2.2]octane-1-carboxylic acid, 0.096 molof 1,4-cyclohexanedimethanol (cis/trans=31/69), and 0.023 mol ofneopentyl glycol. A polyester (Poly[(1,4-cyclohexanedimethylene1,4-bicyclo[2.2.2]octanedicarboxylate)-co-(neopentylene1,4-bicyclo[2.2.2]octanedicarboxylate)],1,4-cyclohexanedimethylene:neopetylene=85:15) with an IV of 0.610, aT_(g) of 110° C., and a T_(m) of 255° C. was obtained. Thecrystallization half-time for this material was then measured atmultiple temperatures with measured crystallization half-times asfollows: 13.4 min at 160° C., 7.1 min at 170° C., 6.1 min at 180° C.,6.0 min at 190° C., and 7.8 min at 200° C. The sample therefore wascharacterized by a minimum crystallization half-time of 6.0 minutes.

Example 8 (Control)

The procedure used to form a polyester as set forth in Example 5 wasemployed in Example 9 using the following monomer composition: 0.10 molof 4-(methoxycarbonyl)bicyclo[2.2.2]octane-1-carboxylic acid, 0.088 molof 1,4-cyclohexanedimethanol (cis/trans=31/69), and 0.030 mol ofneopentyl glycol. A polyester (Poly[(1,4-cyclohexanedimethylene1,4-bicyclo[2.2.2]octanedicarboxylate)-co-(neopentylene1,4-bicyclo[2.2.2]octanedicarboxylate)],1,4-cyclohexanedimethylene:neopetylene=80:20) with an IV of 0.765, aT_(g) of 116° C., and a T_(m) of 244° C. was obtained. Thecrystallization half time of this material between 110° C. to 200° C.was considerably slow (longer than 30 minutes) and was therefore notdetermined.

The foregoing description of various embodiments of the invention hasbeen presented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the preciseembodiments disclosed. Numerous modifications or variations are possiblein light of the above teachings. The embodiments discussed were chosenand described to provide the best illustration of the principles of theinvention and its practical application to thereby enable one ofordinary skill in the art to utilize the invention in variousembodiments and with various modifications as are suited to theparticular use contemplated. All such modifications and variations arewithin the scope of the invention as determined by the appended claimswhen interpreted in accordance with the breadth to which they arefairly, legally, and equitably entitled.

That which is claimed is:
 1. A semi-crystalline polyester comprising arepeat unit of the formula:

wherein A is an aliphatic, aromatic, or heterocyclic group; R₁ isselected from the group consisting of 1,4-butanediol residue and1,4-cyclohexanedimethanol residue; R₂ is neopentanediol residue; m isbetween 50 and 99 inclusive; n is between 1 and 50 inclusive; x isbetween 1 and 200 inclusive; and wherein said semi-crystalline polyesterexhibits a minimum crystallization half-time of about 0.3 minutes orgreater.
 2. The semi-crystalline polyester of claim 1 wherein saidminimum crystallization half-time is 0.5 minutes or greater.
 3. Thesemi-crystalline polyester of claim 2 wherein said minimumcrystallization half-time is 0.6 minutes or greater.
 4. Thesemi-crystalline polyester of claim 1 wherein said semi-crystallinepolyester has a melt point of between 240° C. and 275° C.
 5. Thesemi-crystalline polyester of claim 1 wherein R₁ is 1,4-butanediolresidue.
 6. The semi-crystalline polyester of claim 1 wherein R₁ is1,4-cyclohexanedimethyl residue.
 7. The semi-crystalline polyester ofclaim 1 wherein m is between 65 and 95 inclusive.
 8. Thesemi-crystalline polyester of claim 1 wherein n is between 5 and 35inclusive.
 9. The semi-crystalline polyester of claim 1 wherein n isbetween 10 and 20 inclusive.
 10. A composition comprising thesemi-crystalline polyester of claim
 1. 11. The composition of claim 10further comprising at least one ingredient selected from the groupconsisting of reinforcements, mold release additives, fillers, surfacefriction modifiers, light and heat stabilizers, extrusion aids,antistatic agents, colorants, dyes, pigments, fluorescent brighteners,antimicrobials, anticounterfeiting markers, hydrophobic and hydrophilicenhancers, viscosity modifiers, slip agents, tougheners, adhesionpromoters toners and colorants.
 12. A film comprising thesemi-crystalline polyester of claim
 1. 13. The film of claim 12 whereinsaid film is a monolayer film.
 14. The film of claim 13 wherein saidmonolayer film is biaxially oriented.
 15. The film of claim 12 whereinsaid film is the backsheet of a photovoltaic module.
 16. The film ofclaim 12 wherein said monolayer film is the backsheet of a photovoltaicmodule.
 17. A photovoltaic module comprising the film of claim
 12. 18.An injection molded article comprising the semi-crystalline polyester ofclaim 1.